As God does not feel resentment, He is incapable of hate or harbouring bad feelings towards anyone. This attitude of God was demonstrated by the example of Christ on the cross. Imagine if you could do this - look on dispassionately as people treat you terribly, even kill you. Wouldn't most people resent their tormentors? Wouldn't they be angry? Wouldn't they curse them? Want to take revenge on them? - this is the human reaction. God, however - as demonstrated by Christ - is above such emotions. He would not allow whatever people do to Him to diminish His love for them in any way.
What about God's judgement you ask? What about His wrath - that we read so much about in the old testament? The flood, the destruction of Sodom and Gomorrah? Let me suggest that people - even the authors of the old testament - tend to interpret these events and actions from a human perspective. This is the way of people - the pagan gods for example, were all seen as being subject to human desires and emotions. It seems that most people cannot imagine an intelligent, loving being that is not weak like themselves in relation to other emotions. Well God is not like us. What we see as wrath is merely God's wisdom at work. If unfortunate events must befall people, then these happen, or are allowed, for the ultimate benefit of people. God certainly does not allow these out of anger - but He might out of wisdom. Just as a parent might send a child to bed, or allow the child to fail at some task as a learning experience. The parent acts only out of love, and so does God.
What about judgement you ask? All the bad things we do? Does He not hold us to account for these? My answer is that God does not seek to punish us for our sins - He does not need to judge us and punish us - we ourselves will be our own judges - our own conscience will judge us and our actions. God seeks only to allow us to see our errors of understanding and behaviour. He allows us to see the consequences of our actions - sparking within us the recognition of what is right and wrong in what we and others do. But far be it from God to seek to judge us with the intention of looking at us with less love or care, or worse, seeking to punish us out of frustration or anger as a human might do.
So what about us weak humans? What can we do? We have no control over our emotions - we cannot help but feel resentment when mistreated. We cannot help but feel anger and frustration at times. Well this is true - as long as we stay as natural humans we will be subject to all these weaknesses - but it need not be this way. We can chose to become like God - in fact we are all called to such a destiny - we are all called to become 'God's children' - in the likeness of God (spiritual likeness that is). If you follow this path you will see yourself gradually change - your human nature will become more and more a Godly nature. Your spirit will gain control over your body and your passions. You will separate yourself - raise yourself if you like - above nature. Feelings of resentment will beat futilely at your door - as your strengthened spirit stands like a strong castle wall on which wild winds have no effect. Anger will be more and more easily be held at bay. Love will prevail - even in the face of mistreatment and selfishness. And best all of - fear will receed - fear of failure, fear of the opinions of others, fear of the future, fear of death - all this will dissipate. You will feel yourself becoming more and more like Christ in your spirit. You will identify more and more with how He felt on the cross - you understand deep in your soul how He could only feel love, and how far feelings of anger and resentment would be from his heart.
And it is beautiful. It is joyous. Imagine having no fear. Imagine feeling only love. Imagine having space in your heart and life for joy instead of anxiety, insecurity, instead of fear, resentment and anger. Imagine the blissfulness of being such a blessed being. Imagine being free from the passions and calls of hunger, of lust, of pain. All these things come more and more under your control as you separate yourself from your physical human nature, and you become more and more spiritual. Your body and your desires become not part of you, but something outside of you - something which you - as a spiritual being - now have control over. How could you not? Everything is subject to the power and will of God, so the closer you get to God in yourself, in your inclinations and control, the more these things must become subject to you. It is not a lust for power that drives you - it is lust for pure love, and the inevitable consquence is the conquering of your human nature and mastery of of the entire natural world. If you think about it, nature and the spiritual world could not be organised, nor exist, any other way.